Nelson, AnnGhalsasi, Akshay Anant2017-08-112017-08-112017-08-112017-06Ghalsasi_washington_0250E_17269.pdfhttp://hdl.handle.net/1773/40286Thesis (Ph.D.)--University of Washington, 2017-06We have consensus models for both particle physics (i.e. standard model) and cosmology (i.e. $\Lambda$CDM). Given certain assumptions about the initial conditions of the universe, the marriage of the standard model (SM) of particle physics and $\Lambda$CDM cosmology has been phenomenally successful in describing the universe we live in. However it is quite clear that all is not well. The three biggest problems that the SM faces today are baryogenesis, dark matter and dark energy. These problems, along with the problem of neutrino masses, indicate the existence of physics beyond SM. Evidence of baryogenesis, dark matter and dark energy all comes from astrophysical and cosmological observations. Cosmology also provides the best (model dependent) constraints on neutrino masses. In this thesis I will try address the following problems \textbf{1)}Addressing the origin of dark energy (DE) using non-standard neutrino cosmology and exploring the effects of the non-standard neutrino cosmology on terrestrial and cosmological experiments. \textbf{2)} Addressing the matter anti-matter asymmetry of the universe.application/pdfen-USnoneParticle physicsPhysicsThesis